1. Field of Invention
This Invention relates to a windscreen wiper. More particularly, the invention relates to a windscreen wiper assembly and to a coupler for a windscreen wiper assembly.
2. Description of the Related Art
WO-A-98/19 899 discloses a windscreen wiper assembly having a wiper arm, a windscreen wiper with a resiliently flexible elongate beam which is curved in a plane, and a coupler for coupling an end of the wiper arm to the wiper. However, with this prior art assembly the beam is tightly gripped and flexing movement of the beam in the coupler is inhibited. This impairs operation of the wiper.
Thus, according to the invention there is provided a coupler for coupling an end of a wiper arm to a windscreen wiper having a resiliently flexible elongate beam which is curved in a plane, comprising
a support structure; and
a mounting means for mounting the support structure to the beam;
characterized therein that the coupler has at least one spacing formation carried by the support structure, engageable in use with an upper surface of the beam, for spacing the upper surface of the beam a predetermined distance from the support structure, thereby to provide a space in which the beam can flex, in use.
The invention extends to a windscreen wiper assembly which includes a windscreen wiper having a resiliently flexible elongate beam which is curved in a plane and a coupler in accordance with the invention engaged therewith.
At least one spacing formation may comprise a fulcrum formation which permits, in use, bending movement of the beam about the formation in the plane of curvature.
Preferably there may be a pair of spaced spacing formations.
The support structure may have an elongate, substantially planar base with the spacing formations being defined on a bottom surface of the base. Each spacing formation may comprise an elongate protrusion located transversely to the base end, in use, transversely to the plane of curvature of the beam. Each protrusion may have a rounded or sharpened edge to allow bending of the beam thereabout.
The mounting means may comprise two pairs of spaced apart claws which extend from the base. Each of the spacing formations may be proximate or aligned with one of the pairs of claws.
The spacing between the upper surface of the beam and the bottom surface of the support structure may be sufficient to permit flexing, in use, of the beam.
The spacing between the claws of each pair may be substantially equal to the width of the beam at that position in order to inhibit pivoting or twisting of the beam about its longitudinal axis and to impede relative lateral movement.
The beam may have a securing formation complementary to one of the pairs of claws for securing the support structure to the beam so that longitudinal movement of the beam relative to the coupler at that point is impeded. Those skilled in the art will appreciate that relative longitudinal movement will be permitted between the beam and the support structure at the pair of claws spaced from the securing formation.
The coupler may thus be mounted to the wiper such that longitudinal movement of the beam relative to a point on the coupler, rotation of the beam about its longitudinal axis and rotation of the longitudinal axis of the beam relative to the longitudinal axis of the arm (known as fish talling) are substantially inhibited.
The assembly may also include a connecting structure for pivotally connecting the end of the wiper arm to the wiper to allow pivotal movement of the wiper arm relative to the wiper in the plane of curvature. It will be appreciated that the connecting structure may form a part of the coupler or of the arm or a combination of both.
It will be appreciated that the wiper performs better with a coupler in accordance with the invention as the beam is able to flex about the spacing formations inside the coupler.
It will also be appreciated that the windscreen wiper assembly as described above significantly reduces the height required between a windscreen and a vehicle bonnet in order to improve wind flow over the vehicle and allow the windscreen wiper assembly and arm to be hidden below the vehicle bonnet.
It will be appreciated further that the invention has specific application to a low profile wiper and that the coupler is designed to minimise distance or space between the bottom surface of the support structure and the upper surface of the beam whilst still providing sufficient space for the beam to flex. It will also be appreciated that the distance or space is dependent on the distance between the spacing formations and will accordingly be larger when the spacing formations are further apart to allow for bending movement of the wiper between the points of contact. A height dimension from a bottom edge of a rubber which is mounted to the beam of the wiper and the highest protrusion of the coupler may be less than 25 mm and preferably is less than 20 mm.